\(\frac{36^{10}\cdot5^{10}}{75^{10}\cdot5^{10}}\)
\(\frac{6^6+6^3\cdot3^3+3^6}{-73}-\frac{45^{10}\cdot5^{20}}{75^{15}}\)
Giúp mình với !
\(^{\frac{15^{19}\cdot5^{10}}{9^{10}\cdot25^{14}}}\)
bn vt lớn dữ z -.-
\(\frac{15^{19}.5^{10}}{9^{10}.5^{14}}=\frac{3^{19}.5^{19}.5^{10}}{3^{20}.5^{14}}=\frac{3^{19}.5^{29}}{3^{20}.5^{14}}=\frac{5^{15}}{3}\)
\(\frac{15^{19}.5^{10}}{9^{10}.5^{14}}=\frac{3^{19}.5^{19}.5^{10}}{3^{20}.5^{14}}=\frac{3^{19}}{3^{20}}.\frac{5^{29}}{5^{14}}\)\(=\frac{1}{3}.\frac{5^{15}}{1}=\frac{5^{15}}{3}\)
Vậy ...
Học tốt ^^
Rút gọn :\(\frac{2\cdot3\cdot5+4\cdot9\cdot25+6\cdot9\cdot35+10\cdot21\cdot40}{2\cdot3\cdot5+4\cdot9\cdot35+6\cdot9\cdot49+10\cdot21\cdot56}\)
Tính:
\(\frac{790^{^4}}{79^{^4}}\)
\(\frac{8^{^{14}}}{4^{^{12}}}\)
\(\frac{2^{^{15}}\cdot9^{^4}}{6^{^6}\cdot8^{^3}}\)
\(\frac{45^{^{10}}\cdot5^{^{10}}}{75^{^{10}}}\)
\(\frac{6x-5}{10+10}=\frac{1}{1\cdot3}+\frac{1}{3\cdot5}+...+\frac{1}{49\cdot51}\)
VT = 1/2.( 1-1/3+1/3-1/5+...+ 2/49-1/51)
= 1/2. 50/51
=> 6x-5/10+10 = 25/51
............. Tụ làm phàn còn lại nhé
Nhân cả 2 vê với 2 ta được:
\(\frac{2.\left(6x-5\right)}{20}\)=\(\frac{2}{1.3}\)+\(\frac{2}{3.5}\)+...+\(\frac{2}{49.51}\)
<=>\(\frac{6x-5}{10}\)=\(1-\frac{1}{3}+\)\(\frac{1}{3}-\frac{1}{5}+...+\frac{1}{49}-\frac{1}{51}\)
<=>\(\frac{6x-5}{10}=1-\frac{1}{51}\)
<=>\(6x-5=\frac{50}{51}.10\)
<=>\(x=\frac{755}{306}\)
mấy bn ơi mik lỡ ghi đề sai z
đề đúng là \(\frac{6x-5}{10x+1}=\frac{1}{1.3}+\frac{1}{3.5}+...+\frac{1}{49.51}\)
a, Rút gọn phân số :
\(\frac{\left(-2\right)^3\cdot3^3\cdot5^3\cdot7\cdot8}{3\cdot5^3\cdot2^4\cdot42}\)
b, so sánh không qua quy đồng :
A=\(\frac{-7}{10^{2005}}\)+\(\frac{-15}{10^{2006}}\)
B=\(\frac{-15}{10^{2005}}\)+\(\frac{-7}{10^{2006}}\)
két bn vớ mk . mk bày cho chớ làm vào đây tốn thời gian lắm
\(A=\frac{\left(-2\right)^3\cdot3^3\cdot5^3\cdot7\cdot8}{3\cdot5^3\cdot2^4\cdot42}\)
\(=\frac{\left(-2\right)^3\cdot3^3\cdot6^3\cdot5^3\cdot7\cdot2^3}{3\cdot5^3\cdot2^4\cdot2\cdot3\cdot7}\)
\(=\frac{\left(-2\right)^3\cdot3^8\cdot5^3\cdot2^3\cdot7}{3^2\cdot5^3\cdot2^5\cdot7}=-2\cdot3^6\)
câu b để nghĩ...
Rút gọn biểu thức:
\(\frac{2^{12}\cdot13+2^{12}\cdot65}{2^{10}\cdot104}+\frac{3^{10}\cdot11+3^{10}\cdot5}{3^9\cdot2^4}\)
\(\frac{2^{12}.13+2^{12}.65}{2^{10}.104}+\frac{3^{10}.11+3^{10}.5}{3^9.2^4}\)
\(\Rightarrow\frac{2^{12}.\left(13+65\right)}{2^{10}.104}+\frac{3^{10}.\left(11+5\right)}{3^9.2^4}\)
\(\Rightarrow\frac{2^{12}.78}{2^{10}.104}+\frac{3^{10}.2^4}{3^9.2^4}\)
\(=\frac{2^2.3}{4}+3\)
\(=3+3=6\)
\(\frac{20^5\cdot5^{10}}{100^5}\)
\(\frac{20^5.5^{10}}{100^5}=\frac{5^5.4^5.25^5}{100^5}=\frac{5^5.100^5}{100^5}=5^5=3125\)
\(\frac{20^5.5^{10}}{100^5}\)= \(\frac{5^5.4^5.5^5.5^5}{5^5.4^5.5^5}\)= \(5^5\)= \(3125\)
Rút gọn \(A=\frac{2\cdot6\cdot10+6\cdot10\cdot14+10\cdot14\cdot18+...+194\cdot198\cdot202}{1\cdot3\cdot5+3\cdot5\cdot7+...+97\cdot99\cdot101}\)
\(\frac{2.6.10+6.10.14+10.14.18+...+194.198.202}{1.3.5+3.5.7+...+97.99.101}\)
\(=\frac{2^3.1.3.5+2^3.3.5.7+2^3.97.99.101}{1.3.5+3.5.7+...+97.99.101}\)
\(=\frac{2^3\left(1.3.5+3.5.7+...+97.99.101\right)}{1.3.5+3.5.7+...+97.99.101}\)
\(=\frac{2^3}{1}=8\)
Vậy A = 8